Image capture apparatus

ABSTRACT

An image capture apparatus has an image capture unit to capture an object image, an acquisition unit to acquire a developing parameter for image data captured by the image capture unit, an analysis unit to analyze RAW image data generated by the image capture unit, an image composition unit to compose a plurality of RAW image data generated by the image capture unit and generate composite RAW image data, a composition ratio determination unit to determine a composition ratio for a plurality of developing parameters respectively for development of the plurality of RAW image data acquired by the acquisition unit, a parameter composition unit to compose the plurality of developing parameters and generate one composite developing parameter, and a development unit to develop the composite RAW image data using the composite developing parameter.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 12/814,125,filed Jun. 11, 2010 the entire disclosure of which is herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image capture apparatus capable ofmultiple-exposure image capture.

2. Description of the Related Art

Conventionally, as an image processing apparatus to produce onecomposite image from plural captured images upon multiple-exposure imagecapture, an apparatus to record information to restore captured imagesbefore composition in tag information of a composite image is proposed(see Japanese Patent Laid-Open No. 2002-300372).

Further, an apparatus to convert captured images before compositionusing plural image capturing information upon image capture of pluralimages and perform composition is known (see Japanese Patent Laid-OpenNo. 10-271427).

However, in these conventional techniques, the image capturinginformation stored in a header of a composite image is only imagecapturing information of the first image among the plural capturedimages.

When only the image capturing information upon image capture for thefirst image is recorded as the image capturing information stored in theheader information of the composite image, it is impossible to findobjects in the image capture for the second and the subsequent imagesand as a result it is impossible to determine a developing parameterappropriate for developing the composite image.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above-describedproblems, and sets an appropriate developing parameter for an imagecomposed from plural images acquired by multiple-exposure image capture.

According to a first aspect of the present invention, there is providedan apparatus comprising: an image capture unit to capture an objectimage; an acquisition unit to acquire a developing parameter for imagedata captured by the image capture unit; an analysis unit to analyze RAWimage data generated by the image capture unit; a first composition unitto compose a plurality of RAW image data generated by the image captureunit and generate composite RAW image data; a determination unit todetermine a composition ratio for a plurality of developing parametersrespectively for development of the plurality of RAW image data acquiredby the acquisition unit in accordance with a result obtained from theanalysis unit or a user's setting; a second composition unit to composethe plurality of developing parameters acquired by the acquisition unitbased on the composition ratio for the plurality of developingparameters determined by the determination unit and generate onecomposite developing parameter; and a development unit to develop thecomposite RAW image data composed by the first composition unit usingthe composite developing parameter generated by the second compositionunit.

According to a second aspect, there is provided an apparatus comprising:an image capture unit to capture an object image; an acquisition unit toacquire a developing parameter for image data captured by the imagecapture unit; a first composition unit to compose a plurality of RAWimage data generated by the image capture unit and generate compositeRAW image data; a second composition unit to generate information tocompose a plurality of developing parameters acquired by the acquisitionunit; a recording unit to record the composite RAW image data, theacquired plurality of developing parameters and the information tocompose the plurality of developing parameters; an analysis unit toanalyze the RAW image data recorded by the recording unit; and adetermination unit to determine a composition ratio for the plurality ofdeveloping parameters respectively for development of the plurality ofRAW image data in accordance with a result obtained from the analysisunit or a user's setting, wherein, when the information to compose theplurality of developing parameters is read, the second composition unitcomposes the plurality of developing parameters recorded by therecording unit, based on the composition ratio for the plurality ofdeveloping parameters determined by the determination unit, andgenerates one composite developing parameter.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a configuration of an image captureapparatus according to a first embodiment of the present invention;

FIG. 2 is a flowchart showing an operation to capture plural images andcompose them for multiple exposure in a case where a color conversiontable is composed as a developing parameter;

FIG. 3 is a flowchart showing an operation to capture plural images andcompose them for multiple exposure in a case where a white balance valueis composed as a developing parameter;

FIG. 4 is a graph showing an example of white balance setting;

FIG. 5 is a block diagram showing a configuration of the image captureapparatus according to a second embodiment of the present invention; and

FIG. 6 is a table showing an example of a header format in the secondembodiment of the present invention.

DESCRIPTION OF THE EMBODIMENTS

Hereinbelow, embodiments of the present invention will now be describedin detail in accordance with the accompanying drawings.

First Embodiment

FIG. 1 is a block diagram showing a configuration of an image captureapparatus according to a first embodiment of the present invention. InFIG. 1, reference numeral 101 denotes an image capture unit to capturean object image. The image capture unit 101 has an imaging lens 101 a toform an object image and an image capture device 101 b to performphotoelectric conversion on the formed object image and generate ananalog image signal. The imaging lens 101 a is illustrated as one lensfor the sake of convenience of explanation, however, actually, itincludes a zoom lens for zooming, a focus lens for focusing, an aperturefor light amount control and the like. Numeral 102 denotes an A/Dconverter to convert an analog image signal outputted from the imagecapture unit 101 into digital image data. Numeral 103 denotes a digitalsignal processing unit to generate RAW image data from the digital imagedata outputted from the A/D converter 102. In the present embodiment, toobtain images by multiple exposure, image capture is performed pluraltimes, and plural RAW image data obtained in the respective imagecaptures are stored into a memory 105 for later composition.

Numeral 104 denotes an image capturing information acquisition unit toacquire image capturing information (information upon image capture) inrespective plural image captures for multiple exposure. As imagecapturing information, a color conversion table set value, a whitebalance set value, thumbnail information, exposure time, an aperturevalue, an image capture mode, an ISO film speed value, a shutter speed,a light control correction value, an exposure correction value, lensinformation, a distance to an object, a flash status and the like can begiven. Note that the color conversion table means a table fordetermination of color balance for development of captured RAW imagedata. A user setting unit 107 to be described later sets one of colorbalances for a vivid image, a standard image, a neutral image withsuppressed color development, a flesh-color oriented image and the like,in accordance with a user's preference. Further, the white balance setvalue is set by the user from auto white balance, sunlight, fluorescentlight, a tungsten lamp and the like using the user setting unit 107, orby directly inputting a color temperature. Further, the image capturinginformation includes information on presence/absence of a person's facein a captured image, a face position, a face size and the like obtainedby analysis of RAW image data by an image analysis unit 106 to bedescribed later. The image capturing information in the respectiveplural image captures obtained by the image capturing informationacquisition unit 104 are stored in the memory 105.

The image analysis unit 106 analyzes the RAW image data outputted fromthe digital signal processing unit 103, and detects whether or not aperson's face exists in the image, and when it exists, the position ofthe face, the size of the face and the like. The user setting unit 107enables the user to set a color conversion table set value, a whitebalance set value and the like. Numeral 108 denotes a composition ratiodetermination unit to determine a composition ratio for composition ofdeveloping parameters such as the color conversion table set value andthe white balance set value for the respective plural image data. Adevelopment processing unit 111 performs development processing on RAWimage data composed by an image composition unit 110 using a compositedeveloping parameter selected or composed by a developing parameterselection/composition unit 109 to be described later, based on thecomposition ratio determined by the composition ratio determination unit108.

Note that the composition ratio determination unit 108 determines thedeveloping parameter composition ratio as follows. For example, acomposition ratio for composition of the respective developingparameters for plural captured image data may be simply 1÷a number ofcaptured images. Further, it may be arranged such that based on theexistence/absence of face detected by the image analysis unit 106(detection result), the composition ratio for composition of thedeveloping parameters for face-included image data is increased and acomposite developing parameter with preference on face is generated.Further, it is possible for the user to explicitly set a developingparameter composition ratio using the user setting unit 107.

The developing parameter selection/composition unit 109 composes adeveloping parameter for plural captured image data based on thedeveloping parameter composition ratio determined by the compositionratio determination unit 108. Note that, for example, when a compositedeveloping parameter with preference on face is generated as describedabove, it may be arranged such that a developing parameter for one imagedata where a face exists is selected as a composite developing parameterwithout using a developing parameter for image data without face.

The image composition unit 110 composes plural RAW image data capturedfor multiple exposure. Note that in the image composition by the imagecomposition unit 110, plural RAW image data are composed at a ratio of1:1 without particularly changing the ratio. The development processingunit 111 performs development processing on the RAW image data composedby the image composition unit 110 using the composite developingparameter generated by the developing parameter selection/compositionunit 109. Numeral 112 denotes a recording unit to record the image datadevelopment-processed by the development processing unit 111 in a memorycard or the like.

FIG. 2 is a flowchart showing an operation to capture plural images andcompose them for multiple exposure in a case where a color conversiontable is composed as a developing parameter. Further, the number ofimages to be composed is two. That is, in FIG. 2, image capture by theimage capture unit 101 in FIG. 1 is performed at steps S201 and S205,that is, the image capture is performed twice.

First, at step S201, image capture is performed by the image captureunit 101, then at step S202, it is determined whether or not a face hasbeen detected in the image captured at step S201. The face detection isperformed by utilizing image capturing information obtained from theimage capturing information acquisition unit 104 or information obtainedby the image analysis unit 106 from the captured image. When it isdetermined at step S202 that a face has been detected, the processproceeds to step S203, at which face information indicating theexistence/absence of face, the position of the face, the size of theface, the image from which the face has been detected, is stored in thememory 105. Further, at step S204, the color conversion table set valueobtained by the image capturing information acquisition unit 104 isstored in the memory 105. Then the process proceeds to step S205. Whenit is determined at step S202 that a face has not been detected, thecolor conversion table set value obtained with the image capturinginformation acquisition unit 104 is stored in the memory 105 at stepS204, then the process proceeds to step S205. From step S205 to stepS208, the same processing as that from step S201 to step S204 isperformed.

At step S209, the image composition unit 110 performs image combining,then selection or composition of a color conversion table is performedat step S211 using the developing parameter composition ratio obtainedby the composition ratio determination unit 108. Upon selection orcomposition of a color conversion table at step S211, when, for example,at least one captured image where a face has been detected exists, acolor conversion table appropriate to portrait image can be applied.

Further, a color conversion table LUTm, formed by composing plural colorconversion tables LUT1 and LUT2 as in the following expression, can beapplied.

LUTm(R,G,B)=αLUT1(R,G,B)+(1−α) LUT2(R,G,B)

α is a composition ratio for the first captured image.

At step S212, development processing is performed by the developmentprocessing unit 111 using the composite color conversion table generatedas above as a developing parameter, and a record image is obtained.

In this manner, as one developing parameter is generated by referring toplural image capturing information, even in a case where a landscape isimage-captured as a first image in multiple exposure image capture thena person is image-captured as second and third images, an appropriatedeveloping parameter can be set. For example, by selecting portrait as adeveloping parameter, not development processing specialized for thelandscape as the first image but development processing appropriate tothe second and third portrait images in which a person is captured canbe performed.

FIG. 3 is a flowchart showing an operation to capture plural images andcompose them for multiple exposure in a case where a white balance valueis composed as a developing parameter. Further, in this case, the numberof composed images is two. That is, in FIG. 3, image capture by theimage capture unit 101 in FIG. 1 is performed at steps S301 and S303,that is, performed twice.

When image capture is performed at step S301, then at step S302, a whitebalance set value is stored together with the captured image into thememory 105, and the process proceeds to step S303. When image capture isperformed at step S303, similarly, a white balance set value is storedtogether with the captured image into the memory 105 at step S304, andthe process proceeds to step S305. At step S305, the image compositionunit 110 performs image composition, then at step S307, selection orcomposition of a white balance value is performed using the developingparameter composition ratio obtained by the composition ratiodetermination unit 106. Note that upon acquisition of composition ratio,similar processing to that in the color conversion table can beperformed.

Further, it may be arranged such that a color temperature Tm iscalculated as in the following expression and applied as a weightedaverage from plural color white balance temperatures T1 and T2 inaccordance with a composition ratio.

Tm=αT1+(1−α)T2

Note that α is a composition ratio for the first captured image. Forexample, when T1 is 4000K, T2, 6000K and α is 0.6, a white balance valuecorresponding to 4800K is selected as shown in FIG. 4. At step S308, thedevelopment processing unit 111 performs development processing usingthe generated white balance value as a developing parameter, and arecord image is obtained.

In this manner, as one developing parameter is generated by referring toplural image capturing information, even when plural captured images areobtained with different white balance set values, an appropriatedeveloping parameter can be set. Further, as a weighted average ofplural white balance values is calculated in accordance with acomposition ratio, not development processing specialized for the firstcaptured image but development processing appropriate to a compositeimage can be performed.

Second Embodiment

FIG. 5 is a block diagram showing a configuration of the image captureapparatus according to a second embodiment of the present invention. Inthe second embodiment, information necessary for determination of adeveloping parameter is included in a header of composite RAW image databefore development and the composite RAW image data is recorded. Forthis purpose, in addition to the configuration in the first embodimentshown in FIG. 1, a header information composition unit 509 and arecording unit 511 to record the composite RAW image data together withthe composite header information are provided. Since the otherconstituent elements are the same as those in the first embodiment, thesame elements have the same reference numerals.

In the case of the present embodiment, the header information of thecomposite RAW image data before development is as shown in FIG. 6. InFIG. 6, as a composition parameter, parameters necessary fordetermination of a developing parameter such as face information, acolor conversion table set value, a white balance set value and the likeare recorded.

Hereinbelow, a particular example upon writing of header information asshown in FIG. 6 will be described using FIG. 5. First, processings bythe image capture unit 101 to the composition ratio determination unit108 are the same as those in FIG. 1. In the header informationcomposition unit 509, upon composition of header information, first,information indicating “composed” is written in the header information,and parameters for composition of respective captured images are writtenin other positions in the header. The composite header information isassociated with the composite RAW image data obtained by the imagecomposition unit 110 and recorded.

In the developing parameter selection/composition unit 109, when theinformation indicating “composed” is read, a composition parameter isread from the stored header information and selection or composition ofdeveloping parameter is performed. The development processing unit 111performs development using the developing parameter obtained as above,and the recording unit 112 records a developed image.

As described above, the composite header information is associated withthe composite RAW image data and stored, thereby selection orcomposition of a color conversion table and a white balance upondevelopment processing can be performed while a composition ratio isnewly controlled.

Other Embodiment

In the above-described second embodiment, the image capture apparatusitself performs parameter composition and development with respect toRAW image data recorded by the recording unit 511, however, the presentinvention is not limited to this arrangement. For example, it may bearranged such that application software operating on a personal computerhas functions of the developing parameter selection/composition unit109, the development processing unit 111, the image analysis unit 106,the composition ratio determination unit 108 and the like.

In this case, software (program) to realize the functions of theabove-described embodiments is supplied to a system or an apparatus (forexample, a personal computer) via a network or various storage media,and a computer (or a CPU or an MPU) of the system or apparatus reads andexecutes the program.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2009-156324, filed Jun. 30, 2009 which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. An apparatus comprising: an image capture unit tocapture an object image; an acquisition unit to acquire a developingparameter for image data captured by said image capture unit; ananalysis unit to analyze RAW image data generated by said image captureunit; a first composition unit to compose a plurality of RAW image datagenerated by said image capture unit and generate composite RAW imagedata; a determination unit to determine a composition ratio for aplurality of developing parameters respectively for development of saidplurality of RAW image data acquired by said acquisition unit inaccordance with a result obtained from said analysis unit or a user'ssetting; a second composition unit to compose the plurality ofdeveloping parameters acquired by said acquisition unit based on saidcomposition ratio for the plurality of developing parameters determinedby said determination unit and generate one composite developingparameter; and a development unit to develop the composite RAW imagedata composed by said first composition unit using the compositedeveloping parameter generated by said second composition unit.